Conversion of higher boiling hydrocarbons to lower boiling hydrocarbons



22, 1936. v HENNYv CONVERSION OE' HIGHER BOILING HYDROCARBONS TO LOWER BOILING HYDROCARBON Original Fliled May 7, 1930 suitable for cracking stock. lThe light condensable vapors are lseparated from the uncondensable Patented Sept. 22, 1936 PATENT OFFICE COVERSION OF HIGHER BOILING HYDRO- CARBONS TO LOWER BOILING HYDRO- CARBONS Victor Henny, London, England, assigner, by mesne assignments, to Universal `i`l Products Company, Chicago, Ill., a corporation of Dela- Waffe Application May 7, 1930, Serial No. 450,327 Renewed July 25, 1935 4 Claims.

This invention relates to the conversion vof higher boiling hydrocarbons to lower boiling hydrocarbons, and pertains in its specific embodiment to the separationof a tar oil suitableas cracking stock from the vapors and gases derived from the carbonization of bituminous materials and the conversion of same `at elevated temperatures into anti-knock motor fuel and other products.

It is amongvthe objects of my invention to make use of low-grade coals and coal Wastes as Well as the .higher .gradecoals in the production .of coke and high anti-knock lmotor fuel. The Vcarbonaceous materials used include bituminous coals, cannel coal, brown coal, lignites, peats, etc. My invention is directed vparticular-ly Ytoward-the treatment of the condensable vapors Yproduced in Athe carbonization of these materials. l

Among further objects of myv invention ist `provide a process Where the car-bonization process Yand cracking operationare combined, i. e., a process where the vapor and .gaseous products from the carbonaceous process are treated and a tar oil `suitable as cracking stock separatedand rsubjected to conversion conditions. Advantages are obtained such as heat economy, reduction or elimination of high coke-,forming constituents in the cracking stock, improved yieldsV and quality vof the products, etc.

The ycarbonzation stage of the process is preferably of the low temperature type in which the carbonaceous material is subjected to the relatively low temperature treatment` of approximately v'Z50-1000" F., or more, Where higher yields of oil for cracking 'are obtained 'than in high temperature carbonization and decreased yield of coke and gaseous products, ,The coke isa desirable, smokeless fuel, and the vgases have a muchhigher heating value than'the gases obtained in high temperature carbonization.

`My invention comprises the' .treatment of the vapor and gaseous .products from the carbonization process, .separating the uncondensable gases and light condensable fractions which include motor fuel hydrocarbons and condenses a tar oil gasesby-condensation, and the uncondensable .gases may-.be subsequently processed for recovery of'condensable.products. The tar oil condensate A isdirected to theiconversion stage of my process Awithout.substantial cooling-below its condensation temperature. f f

The invention will be more clearly understood by referring to the attachedrdrawing whichwill be described later, and in which the preferred embodiment of the conversion stage of the process is illustrated. The temperature conditions used at the outlet of the heating element from which theV mixture of heated cracking stock and parn .used by the manipulation of the various valves,

or other means indicated.

Referring now to the attached drawing, which `is a diagrammatic side elevation not drawn to .sca-1e, Vthe tar oil vapors from the retorts of a continuous `carbonization process (not shown) .are introduced .through line I and valve 2 to the condensing column 3 containing suitable dephlegmating` means which cause condensation and separation of the tar oil fraction which is .to be cracked. A suitable Vcooling mediumV is used in the condensing .column 3 and is introduced from 5- a Vsource (not shown) throughline 4 and valve .5 to thesuction side of pump 6 which pumps this oil through line 1 and line 8 with valve 9 by suitable regulation of this latter valve and valve I0 in line II. Cooling may also be effected at the top of condensing column 3 by the introduction of another cooling medium introduced through line I2, regulated by valve I3, fromfa source which will be later described. Uncondensed vapors and non-condensable gases leave the Ytop of the condensing column 3 through line I4 and valve I leading to the condenser and/or cooler I5, and are then directed through line l1 and valve I8 to the receiver I9 where separation of the liquid and gases is effected. The non-condensable gases are removed through line 20, regulated by valve 2l, and may be directed to the low pressure gas line 22 and distributed as will be later described, or may be removed .through line Z3, regulated by valve 24, and disposed of in any suitable manner. The liquid in receiver I 9 is removed through line 25, regulated by valve 26.

The tar oils condensed in the condensate column 3 ow downward `through line 2'! and Valve 28 to lthe suction side of the hot feed pump 29 from which the oil is pumped through line 30 and valve 3i leading to the dephlegmator 32 and/or through the regulating Valve 33 in line 34 into the line 35 where valve 36 may be closed, and then through valve`3-'I into line 42 where it mixes with reflux ais Yto

direct, and possibly indirect, heat transfer relationship with the vapors therein and the condensed oil, reflux condensate, so-ealled, togetherY With the added hydrocarbon oil directed downward through line 39 and valve 40 to the suction side of a hot oil pump 4l which pumps this oil through line 42 and valve 43 to the heating coil 44 located in heating zone 45. The heated products leave the heating coil 44 through line 46 and valve 41, and pass to the reaction zone 48 Where the reaction continues and vaporization, separation and/or deposition take place. Non-vaporiZed oil may be Withdrawn through line 49, regulated by valve 50, and may be directed to storage or any other suitable disposal. The vapors and gases leave the reaction zone 48 through line 5I and valve 52 and enter the dephlegmator 32 Where they are subjected to heat interchange, dephlegmation and cooling, which has been or Will be further described. The treated vapors leave the dephlegmator 32 and pass through line 53 and valve 54 leading to the condenser and/or cooler 55, and the cooled products flovv through line 56 and valve 51 into the receiver 58 Where separation of the liquid product and non-condensable gas is effected.

The uncondensable gases are removed through line 59 and may be directed through valve 60 to the lovv pressure receiver 6I or through valve 62 in line 63 leading into line 22, from Which it may be directed to storage through line 64, regulated by valve 61, or may be directed through line 68, regulated by valve 69, to the heating Zone or to other suitable disposal. The liquid product from the receiver 58 is withdrawn through line 10, regulated by valve 1l, and is directed to the low pressure receiver 6l Where the dissolved gases are separated and released at reduced pressure. The released gases are Withdrawn through line 12 and may be introduced into line 22 by regulation of `the valve 13, or may be released by valve 14 from which they are directed to recovery plant. The regulated portion of the liquid products in receiver 58 may leave through line 15, regulated by valve 16, and ilow to the suction side of pump 11 which may pump this oil through line 18 and valve 19 to the dephlegmator 32 and/or through the line l2 and valve I3, as previously described. The liquid product from the receiver 6| is Withdrawn through line 65, regulated by valve 66.

Any desired portion of the oil introduced Ythrough line 4 and pumped by pump 6, previously referred to, may be directed through valve I0 in line ll into line 38 leading to dephlegmator 32 by the suitable regulation of valves 80, 8l, and 82, and/or a portion or all of this oil may be directed through valve 82 in line l I into the line 35 leading to the hot oil being pumped to the heatingelement 44. During operation of the plant, valves 31 and 36 are usually open so that in case of emergency valve 83 can be readily opened and the contents oi the heating coil 44 dumped.

As Yan illustration of the application of the Yprocess of my invention and results obtained in Yconnection with a continuous, loW temperature Ycarbonization process where canne] coal is being processed, the vapors and gases produced are directed to the condensing column 3, diagrammatically illustrated in the drawing above described. Approximately 6% to '1% of the total condensable materials pass over to the condenser together with the uncondensable gases andare separated as motorrfuel. A 24 gravity topped crude oil is pumped into the condensing column 3 through line 8 which serves to condense the tar oil vapors and furnish additional cracking stock for the process. The mixture of petroleum oil and coal tar condensate, which is approximately of each, is Withdrawn from the condensing column and pumped to the dephlegmator 32 of the 'conversion process. Although many types of operation are possible in the conversion process, such as various forms of residuum operation producing varied amounts of coke as a by-product, the operation here illustrated is of the nonresiduum type in which substantially no nonvaporized residue oil is Withdrawn from the reaction chamber 48, a hard, agglutinated coke being deposited therein and all liquid products being removed from the vapors and gases leaving the top Vof the reaction chamber and passing to the dephlegmator. The temperature of the oil leaving the heating element is approximately 930 F. and the pressure approximately 350 pounds per square inch. A temperature of approximately 500 F. is maintained at the top of the dephlegmator 32 by recirculating the Ycondensed andi cooled overhead product from same. The pressure on the system is controlled `in the present operation atVv two points, rst in line 46 Where the pressure is reduced from approximately 350 pounds to 200 pounds perrsquare inch by the regulation of valve 41, and, second, by maintaining a liquid level in the receiver 58 and releasing the gas from the top of the receiver by means of valve V60. Y

The refined motor fuel resulting from this operation represents approximately 62% based on the total oil charged to the conversion stage of the process. approximately 420 F., and has an anti-knock value of approximately 40% benzol in Pennsylvania straight-run gasoline.

My invention should not be construed as being limited to the above examples of operations or the yields and character of products described, these being given for illustrative purposes only.

I claim as my invention:

1. A process for producing low boiling point oilsfrom heavy petroleum oil and from the vaporous mixture produced in the carbonization of solid pyrobituminous materials which comprises dephlegmating said vaporous mixture in a fractionating Zone to condense and separate heavier fractions therefrom, lightervapors uncondensed by the dephlegmation, passingthe condensed heavier fractions in admixture with said petroleum oil in a restricted stream through a heating zone and subjecting the mixture therein to cracking conditions of temperature and pressure, discharging the heated mixture into a vapor separating zone and separating the same therein into vapors and residuum, subjecting said vapors to reflux condensation in a second fractionating zone independently of said vaporous mixture to condense fractions thereof heavier than the desired loW boiling point oils, returning resultant reflux condensate to the heating zone for further cracking treatment therein, Yfinally condensing the vapors uncondensed by saidreflux condensation thereby forming pressure distillate, and introducing a portion of said pressure distillate into direct Vcontact with said vaporous mixture undergoing dephlegmation inthe first mentioned fractionat-U ing zone.

condensing the The motor fuel has an end point of v 2. A process for producing low boiling point oils from the vaporous mixture produced in the carbonization of solid pyrobituminous materials and simultaneously from petroleum charging stock for a cracking operation, said process comprising subjecting the petroleum charging stock to cracking conditions of temperature and pressure in a cracking zone, removing the cracked vapors and dephlegmating the same in a fractionating zone, simultaneously dephlegmating said vaporous mixture in a fractionating zone independently of said vaporous mixture in contact with fresh petroleum charging stock, introducing the resultant mixture of reflux condensate and charging stock to the rst-mentioned fraotionating zone as a direct contact dephlegmating medium in the dephlegmation of said cracked vapors, and then supplying said resultant mixture together with reflux condensate formed by the last-named dephlegmation to the cracking zone.

3. A process for producing 10W boiling point oils from the vaporous mixture produced in the carbonization of solid pyrobituminous materials and simultaneously from petroleum charging stock for a cracking operation, said process comprising dephlegmating said vaporous mixture in a fractionating zone in contact with the petroleum charging stock, thereby forming a mixture of tar oil condensate and petroleum charging stock, supplying the last named mixture to a carbonization of solid pyrobituminous materials and simultaneously from petroleum charging stock for a cracking operation, said process comprising dephlegmating said vaporous mixture in a fractionating zone in contact With the petroleum charging stock, thereby forming a mixture of tar oil condensate and petroleum charging stock, supplying the last named mixture to a i cracking zone and cracking the same therein, iractionating the cracked vapors thus formed in a second fractionating zone independently of said vaporous mixture to condense heavier fractions thereof and returning resultant reflux condensate to the cracking zone, finally condensing the fractionated cracked vapors and introducing a portion of the resultant final condensate into contact with said vaporous mixture undergoing dephlegmation. f

VICI'CR HENNY. 

